AMD is having commitment with GLO-Fo for some minimum number order.hence 12 nm product has to be there.with upcoming second Gen from TSMC there may be some serious price cut from obsoleting 12nm node of glo-fo as they are not even into R&D of better mfg node.
It seems that AMD has confirmed that Ryzen processors are coming to Chromebooks. Lenovo may be one of the first OEMs to release a Ryzen-powered Chromebook too.